CVE-2026-43186ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()
Updated under an hour ago ()
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In the Linux kernel, the following vulnerability has been resolved: ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data() On the receive path, __ioam6_fill_trace_data() uses trace->nodelen to decide how much data to write for each node. It trusts this field as-is from the incoming packet, with no consistency check against trace->type (the 24-bit field that tells which data items are present). A crafted packet can set nodelen=0 while setting type bits 0-21, causing the function to write ~100 bytes past the allocated region (into skb_shared_info), which corrupts adjacent heap memory and leads to a kernel panic. Add a shared helper ioam6_trace_compute_nodelen() in ioam6.c to derive the expected nodelen from the type field, and use it: - in ioam6_iptunnel.c (send path, existing validation) to replace the open-coded computation; - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose nodelen is inconsistent with the type field, before any data is written. Per RFC 9197, bits 12-21 are each short (4-octet) fields, so they are included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to 0xff1ffc00).
- CVSS
- 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 before f4d9d4b8fd839719d564651671e24c62c545c23b; from 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 before fb3c662fafebc5b9d74417ed1de8759f6bb72143; from 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 before 632d233cf2e64a46865ae2c064ae3c9df7c8864f; from 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 before 0591d6509c2ff13f09ea2998434aba0c0472e978; from 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 before e90346a2f1e8917d5760a44a1f61c44e3b36d96b; from 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 before ea3632aefc04205436868541638e26f4a74d5637; 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 builds before 6db8b56eed62baacaf37486e83378a72635c04cc | CNA record |
linux linux_kernel linux:linux_kernel | from 5.15 before 5.15.202; from 5.16 before 6.1.165; from 6.2 before 6.6.128; from 6.7 before 6.12.75; from 6.13 before 6.18.16; from 6.19 before 6.19.6 | NVD |
References
- https://git.kernel.org/stable/c/f4d9d4b8fd839719d564651671e24c62c545c23bpatch
- https://git.kernel.org/stable/c/fb3c662fafebc5b9d74417ed1de8759f6bb72143patch
- https://git.kernel.org/stable/c/632d233cf2e64a46865ae2c064ae3c9df7c8864fpatch
- https://git.kernel.org/stable/c/0591d6509c2ff13f09ea2998434aba0c0472e978patch
- https://git.kernel.org/stable/c/e90346a2f1e8917d5760a44a1f61c44e3b36d96bpatch
- https://git.kernel.org/stable/c/ea3632aefc04205436868541638e26f4a74d5637patch
- https://git.kernel.org/stable/c/6db8b56eed62baacaf37486e83378a72635c04ccpatch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.